On Tue, Jan 8, 2019 at 11:08 AM, DJ Delorie

<dj@...> wrote:

"Bill in OKC too via Groups.Io" <wmrmeyers=yahoo.com@groups.io> writes:
> I would suggest you make a stub spindle that duplicates the thread of
> your spindle so you have a way to test your backplate as you work on
> it without having to take your chuck or faceplate off the lathe.

I will add to this to measure the actual thread diameter at both ends of
the spindle.  I suspect mine (model 34, also 1-7/8 13") is a bit
tapered, so if I were to make a stub spindle as a reference for the real
spindle, I'd want to replicate this slight taper as closely as I can.

As for HOW to do that, well, I think I'll cheat and just prop up one leg
of the lathe a bit to twist it enough to do the taper.  Not something I
*want* to do, but how else?  My headstock doesn't rotate at all...

On Tue, Jan 8, 2019 at 11:06 AM, Guenther Paul

<paulguenter@...> wrote:

Here is a easy way. Set up your back plate for the chuck find out the thread depth of the threads you need to cut, bore out your back plate to the proper size. on the front and back of the hole machine a shoulder 3/16 to 1/4 you can do that with you treading tool. thread the plate and when you get close to the depth start fitting your new backplate to the spindle of the lathe. You do that by unthreading the chuck your using don't remove the new back plate from the chuck your using. When you need to put the chuck back on the spindle the new threaded plate will be in the proper position and you can cut the tread deeper if needed.

Making a stub is a total waist of time

GP

--------------------------------------------

On Tue, 1/8/19, Bill in OKC too via Groups.Io <wmrmeyers=yahoo.com@groups.io> wrote:

Subject: Re: [SouthBendLathe] 4 jaw chuck for small spindle 13 in sb

To: "SouthBendLathe@groups.io" <SouthBendLathe@groups.io>

Date: Tuesday, January 8, 2019, 11:53 AM

I would suggest you make

a stub  spindle that duplicates the thread of your spindle

so you have a way to test your backplate as you work on it

without having to take your chuck or faceplate off the

lathe.

The photo, if it works, is of the second

successful external thread I've cut since my high school

machine shop class. It is is fitted to the chuck that came

with my "new" SB 10L. The first was for my Atlas

TH42.

Bill

in OKC

On Tue, Jan 8, 2019 at 10:35 AM,

Sloot2@...<Sloot2@...>

wrote:  I'm in need of a 4 jaw for a south

bend 13 in with the small internal diameter spindle. Buying

an inexpensive chuck isn't a problem but the backing

plate is. I know that there is a way to make your own but

I'm a brand newbie. I have a 3 jaw now   Can I open up

and re thread a backing plate that is already finished as a

1&3/4 x 8 to the opening for mine which I believe is

1&7/8x8. Or am I over thinking or is that not going to

work. This would be my first attempt at internal

threading. 

Rick 

 

On Tue, Jan 8, 2019 at 10:35 AM, Sloot2@...

<Sloot2@...> wrote:

I'm in need of a 4 jaw for a south bend 13 in with the small internal diameter spindle. Buying an inexpensive chuck isn't a problem but the backing plate is. I know that there is a way to make your own but I'm a brand newbie. I have a 3 jaw now   Can I open up and re thread a backing plate that is already finished as a 1&3/4 x 8 to the opening for mine which I believe is 1&7/8x8. Or am I over thinking or is that not going to work. This would be my first attempt at internal threading. 
Rick 

On Mon, Jan 7, 2019 at 10:44 PM, Don Verdiani via Groups.Io

<DLVerdiani@...> wrote:

I'm a Heavy 10 guy. I find myself with a bunch of greater than 3/4" #3 Morse taper shank drills and am wondering. I could easily make a sleeve to put #3 MT drills in the S/B spindle. I have a sleeve with a  #2 MT, no big deal to make another for #3.  It means learning to set work up on the cross slide, but I bet I can figure that out. Anyone tried this? Is it worth doing?

Don V.
West Chester, PA

[Edited Message Follows]

Looks like you could cut most common metrics with a 32 and 34 tooth stud gear. (assuming yours is 36, if it's 18, then you'd need a 16 and 17)

See here:
https://www.practicalmachinist.com/vb/south-bend-lathes/metric-threads-16-sb-231828/

kitno455 is still active so you could PM him.

I cut all my metric threads by just changing the stud gear on my 9A (no transposing gear set needed) and it has been close enough every time.

[Edited Message Follows]

Hey Alan
Is there a similar solution for those of us that don't have a 48 tooth stud gear?

I have the gearbox that covers the range of 2 to 112 TPI, I have a 20 or 40 tooth gear on the stud. Are there a couple of gears that we could use and get a selection of metric threads? I have a heavy 10 with a dual lever gearbox.

Unfortunately there is no such tag. My bed is 48 inches long and it is 5 1/2 inches wide. The center of the spindle is 4 1/2 inches above the bed. I have not measured everything on it but I'm pretty sure it's a 9 by 48. The research I've done has convinced me it's late 1938 or early 1939 manufactured date. I'm probably going to buy the rebuild kit off of Amazon and try to rebuild it.